package study;


import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import com.alibaba.csp.sentinel.slots.system.SystemBlockException;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


/**
 *  限流异常
 **/
@Service
public class CustomUrlBlockHandler implements BlockExceptionHandler {
    @Override
    public void handle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException ex) throws Exception {
        String msg = null;
        if (ex instanceof FlowException) {
            msg = "限流了";
        } else if (ex instanceof DegradeException) {
            msg = "降级了";
        } else if (ex instanceof ParamFlowException) {
            msg = "热点参数限流";
        } else if (ex instanceof SystemBlockException) {
            msg = "系统规则（负载/...不满足要求）";
        } else if (ex instanceof AuthorityException) {
            msg = "授权规则不通过";
        }
        httpServletResponse.setHeader("Content-Type", "application/json;charset=UTF-8");
        String message = "{\"code\":999,\"msg\":\"访问人数过多，+"+msg+"\"}";
        httpServletResponse.getWriter().write(message);
    }

}

